Circular No. 08/2014/TT-BTNMT on technical guidelines for mapping groundwater quality at a scale of 1:25,000

CIRCULAR
Technical Regulations for the Preparation of Groundwater Quality Maps at Scale 1:25,000

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Based on the Law on Water Resources No. 17/2012/QH13 dated June 21, 2012;

Pursuant to Decree No. 21/2013/NĐ-CP dated March 4, 2013, promulgated by the Government, stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

XAt the proposal of the Director of the Water Resources Management Department; the Director of the National Center for Water Resources Planning and Investigation; the Head of the Science and Technology Department and the Head of the Legal Affairs Department;

BThe Minister of Natural Resources and Environment issues this Circular on Technical Regulations for the Preparation of Groundwater Quality Maps at Scale 1:25,000.

PART I
GENERAL PROVISIONS

Article 1. Scope of Regulation and Applicability

Article 1. This Circular specifies the detailed contents and technical requirements for preparing groundwater quality maps at scale 1:25,000 and their products.

Article 2. This Circular applies to state management agencies for water resources, organizations, and individuals who prepare groundwater quality maps at scale 1:25,000.

Article 3. Purpose of Preparing Groundwater Quality Maps at Scale 1:25,000

Point 1. To present the results of groundwater resource investigation and assessment work at scale 1:25,000 or larger scales and related research on water quality.

Point 2. To serve state management of water resources and groundwater exploitation and utilization in areas with polluted groundwater, saline intrusion zones, and protected sanitary zones of groundwater extraction facilities.

Point 3. To meet the needs of information exploitation for relevant sectors, localities, organizations, and individuals involved in groundwater exploitation and utilization activities.

Article 4. Base Maps for Preparing Groundwater Quality Maps at Scale 1:25,000

Point 1. Groundwater quality maps at scale 1:25,000 are prepared based on topographic base maps and hydrogeological base maps at the same scale or larger scales.

Point 2. The topographic base map is a topographic map at scale 1:25,000 (VN-2000 coordinate system) or a larger scale map adjusted to scale 1:25,000.

The topographic map serves as the basis for representing topographical elements according to current regulations: mathematical foundation, topography, hydrographic systems, vegetation, transportation, population, administrative boundaries, territorial boundaries.

Point 3. The hydrogeological base map is a hydrogeological map at scale 1:25,000 (VN-2000 coordinate system) or a larger scale map adjusted to scale 1:25,000.

The hydrogeological map serves as the basis for determining specialized elements: distribution of aquifer layers, non-aquifer formations, total mineralization, chemical composition.

Point 4. In cases where there is no existing hydrogeological map in the study area, it is necessary to conduct surveys and draw up a hydrogeological map containing sufficient information to prepare the groundwater quality map.

Article 5. Mathematical Foundation of Groundwater Quality Maps at Scale 1:25,000

Point 1. Groundwater quality maps at scale 1:25,000 are established in the National Geodetic Reference System and Coordinate System VN-2000 with the following characteristics: Global Ellipsoid WGS-84 suitable for Vietnam's territory; International UTM Projection System; Zone 6, scale factor for length distortion ko = 0.9996.

Point 2. The projection zone and central meridian will be specified in Circular No. 973/2001/TT-TCĐC dated June 20, 2001, issued by the General Department of Land Administration guiding the application of the National Geodetic Reference System and Coordinate System VN-2000.

Article 5. Technical inspection work, product acceptance

Technical inspection work and product acceptance shall be carried out in accordance with the current regulations of the Ministry of Natural Resources and Environment.

Article 6. Types of products

1. Products of groundwater quality maps at a scale of 1:25,000 include:

a) Groundwater quality map at a scale of 1:25,000 and cross-sections;

b) Groundwater quality maps for important aquifers or aquifer systems at a scale of 1:50,000;

c) Appendices containing data for map compilation: Chemical component statistics and groundwater quality records;

d) Special reports: Characteristics of groundwater quality.

2. The products are published in paper and digital formats.

Chapter II
CONTENTS OF GROUNDWATER QUALITY MAPS AT A SCALE OF 1:25,000

Article 7. Base elements

1. Topographic base elements On groundwater quality maps at a scale of 1:25,000, the following topographic base elements must be displayed:

a) Mathematical base layer: Map name, grid frame, elements outside the frame;

b) Topography layer: Contour lines, elevation points and annotations, landform symbols;

c) Hydrographic layer: Sea, rivers, streams, lakes, ponds, canals, embankments, dams, levees... and their names;

d) Vegetation layer: Woody vegetation, herbaceous vegetation, crops;

đ) Transportation layer: Roads, railways, bridges and their names;

e) Settlement layer: Concentrated residential areas, clusters of residences;

g) Administrative layer: For district level including the headquarters of commune, district, county, provincial city directly under the province, and for provincial level including the headquarters of provincial people's committee, centrally governed city; names of administrative units: Commune, district, county, provincial city directly under the province, province, centrally governed city;

h) Boundary layer: Commune, district, county, provincial city directly under the province, province, centrally governed city boundaries, border lines.

Detailed topographic elements must comply with the provisions of geographic information standards issued by the Ministry of Natural Resources and Environment. Topographic base elements may be omitted from 15% to 25% to ensure priority representation of groundwater quality elements.

2. Hydrogeological base elements:

a) Distribution areas of water-bearing and non-water-bearing objects, including: Aquifers and non-aquifer formations;

b) Water-bearing faults, predicted water-bearing faults, and faults with undetermined water-bearing conditions.

Article 8. Professional elements

Professional elements displayed on groundwater quality maps at a scale of 1:25,000 include:

1. Water quality for various uses.

2. Nitrate compounds.

3. Trace element composition.

4. Organic compounds.

5. Microorganisms.

6. Pollution zones, saltwater intrusion zones.

Chapter III
TECHNICAL REPRESENTATION OF GROUNDWATER QUALITY MAPS AT A SCALE OF 1:25,000

Article 9. Principles for representing groundwater quality maps at a scale of 1:25,000

Groundwater quality maps at a scale of 1:25,000 must display the contents of research results conducted in investigating and assessing groundwater resources at a scale of 1:25,000. The contents and information displayed on groundwater quality maps at a scale of 1:25,000 are based on the following principles:

1. Water-bearing units divided according to aquifers and non-aquifer formations, represented by information such as aquifer name, formation name, distribution area, distribution boundary.

2. Areas with different total mineralization levels suitable for different uses are represented by color.

3. Total mineralization (M) of aquifers at locations where analysis results are available is shown at representative points; the saline boundary of covered aquifers is shown by lines of equal value M=1g/l.

4. Pollution indicators of groundwater due to trace element, nitrate compound, microorganism, and organic compound values exceeding Vietnam Technical Regulations (QCVN 09:2008/BTNMT and QCVN 01:2009/BYT) are represented by area and point forms.

5. Chemical composition: Major ions are represented by the dominant concentration symbol at each sampling investigation point and Kurlov formula on cross-sections.

6. Groundwater survey points such as drill holes, dug wells, exposed groundwater points are represented by symbols accompanied by serial numbers and aquifer or aquifer system symbols surveyed.

7. Faults: On groundwater quality maps at a scale of 1:25,000, water-bearing faults, predicted water-bearing faults, and faults with undetermined water-bearing conditions are represented by line forms.

8. Cross-sections: Cross-sections are established along characteristic directions such as perpendicular to structural orientation, along typical groundwater flow direction. The number of cross-section lines is selected depending on specific mapping areas but must ensure comprehensive information representation of the mapped area.

Article 10. Form of Groundwater Quality Map at Scale 1:25,000

1. The name of the map, frame, and label shall be displayed according to the model prescribed in Appendix 3 attached hereto.

2. In cases where the map consists of multiple pieces, a piece assembly diagram shall be shown in the lower right corner of the map frame.

3. The map's annotations are usually placed on the right side of the map frame, while cross-sections are placed below the map frame. In certain cases, annotations may be placed within the map frame at appropriate positions or below the map frame.

4. Size of objects to be depicted

On the groundwater quality map at scale 1:25,000, objects depicted as areas must have a minimum actual width of 50 meters; objects depicted as lines must have an actual length of at least 250 meters.

Article 11. Content Depicted on Groundwater Quality Map at Scale 1:25,000

1. Water-bearing layers and non-water-bearing formations:

a) The boundaries of the first water-bearing layer are represented by continuous purple lines with a thickness of 0.4 mm, and the distribution boundaries of covered water-bearing layers are represented by dashed purple lines with a thickness of 0.7 mm, indicating the direction towards the distribution area, accompanied by water-bearing layer symbols.

b) Non-water-bearing formations are represented by brown areas.

2. Distribution of regions with different total mineralization levels:

a) Total mineralization value scale M (g/l):

- Super fresh water: M <0.1;

- Fresh water: 0.1 ≤ M <1.0;

- Moderately mineralized water: 1.0 ≤ M <1.5;

- Brackish water: 1.5 ≤ M <3.0;

- Saline water: 3.0 ≤ M <10.0;

- Salt water: M ≥10.0.

b) Representation of total mineralization values: For the first water-bearing layer on the map and water-bearing layers in cross-sections, total mineralization will be represented by color according to the following scale:

- Areas with groundwater values from M up to less than 0.1 g/l are represented by light yellow;

- Areas with groundwater values from 0.1 g/l up to less than 1.0 g/l are represented by yellow;

- Areas with groundwater values from 1.0 g/l up to less than 1.5 g/l are represented by light orange;

- Areas with groundwater values from 1.5 g/l up to less than 3.0 g/l are represented by orange;

- Areas with groundwater values from 3.0 g/l up to less than 10.0 g/l are represented by light purple;

- Areas with groundwater values equal to or greater than 10.0 g/l are represented by purple.

c) Boundaries of regions with different total mineralization levels of the first water-bearing layer are represented by continuous green lines with a thickness of 0.7 mm.

3. Total mineralization of covered water-bearing layers

The total mineralization of covered water-bearing layers will be represented in two forms:

a) Salt boundary M=1g/l represented by dashed orange lines with a thickness of 0.7 mm, accompanied by water-bearing layer symbols, with corresponding number of dashes for each water-bearing layer, pointing towards the region with M values greater than 1g/l;

b) Range of M values for water-bearing layers represented by red hatch marks in columns at representative points.

4. Pollution Indicators

Represent components exceeding the limit values of QCVN 09:2008/BTNMT and QCVN 01:2009/BYT.

a) Regions of groundwater contaminated by pollution factors:

- Nitrate compounds: Represented by areas with horizontal striped background in blue, with boundaries of 0.3 mm thick lines of the same color, accompanied by water-bearing layer symbols;

- Trace elements: Represented by areas with vertical striped background in green, with boundaries of 0.3 mm thick lines of the same color, accompanied by water-bearing layer symbols;

- Organic compounds (DDT and lindane): Represented by areas with diagonal 45° striped background in purple, with boundaries of 0.3 mm thick lines of the same color, accompanied by water-bearing layer symbols;

- Microorganisms: Represented by areas with small dot pattern background in light blue, with boundaries of 0.3 mm thick lines of the same color, accompanied by water-bearing layer symbols.

b) Points of groundwater contamination by pollution factors:

- Nitrate compounds: Represented by circles with a diameter of 3 mm, filled with blue in the upper left quarter, accompanied by symbols of those compounds and water-bearing layer symbols in red, shown as fractions;

- Trace elements: Represented by circles with a diameter of 3 mm, filled with green in the upper right quarter, accompanied by symbols of those elements and water-bearing layer symbols in red, shown as fractions;

- Organic compounds (DDT and lindane): Represented by circles with a diameter of 3 mm, filled with purple in the lower right quarter, accompanied by symbols of those compounds and water-bearing layer symbols in red, shown as fractions;

- Microorganisms: Represented by circles with a diameter of 3 mm, filled with light blue in the lower left quarter, accompanied by identification symbols of microorganisms and water-bearing layer symbols in red, shown as fractions;

- Contamination due to a mixture of factors is represented by circles with a diameter of 3 mm, filled with colors corresponding to the respective pollution factors, accompanied by symbols of those compounds and water-bearing layer symbols in red, shown as fractions.

5. Chemical Composition Chemical composition of water at drilling holes, dug wells, and exposed sources is represented by symbols showing the dominant ion concentrations of major elements and Kurlov formula in cross-sections.

6. Groundwater Survey Points:

a) Drilling holes: Represented by black circles with a diameter of 3 mm, accompanied by information such as drilling hole number, surveyed water-bearing layer symbol, total mineralization, and chemical composition;

b) Dug wells: Represented by black squares with sides of 3 mm, accompanied by information such as drilling hole number, surveyed water-bearing layer symbol, total mineralization, and chemical composition;

c) Exposed sources: Represented by black circles with a diameter of 3 mm, with arrows pointing upwards for upward flowing points and downwards for downward flowing points, accompanied by information such as exposed source number, surveyed water-bearing layer symbol, total mineralization, and chemical composition.

7. Faults: Represented by red lines with a thickness of 0.7 mm. Water-bearing faults are represented by continuous lines with crosses (×), predicted water-bearing faults are represented by dashed lines with dots (.), and faults with undetermined water-bearing conditions are represented by dashed lines.

8. Cross-sections: On cross-sections, show the distribution of water-bearing layers and aquitards; different zones of total mineralization within each water-bearing layer; chemical composition and Kurlov formula at drill holes, mark pollution parameters according to QCVN 09:2008/BTNMT and QCVN 01:2009/BYT.

9. The format for representing content and symbols on maps and annotations are detailed in Appendix 1 and Appendix 2 attached to this Circular.

Chapter IV
IMPLEMENTING PROVISIONS

Article 12. Implementation Organization

1. The Minister, Heads of Ministries equivalent to Ministries, Heads of Government agencies, Chairpersons of People's Committees of provinces and centrally governed cities, Director of the National Water Resources Management Agency, General Director of the National Center for Water Resources Planning and Investigation, Heads of units under the Ministry, and related organizations and individuals are responsible for implementing this Circular.

2. The National Water Resources Management Agency is responsible for guiding and supervising the implementation of this Circular.

3. The limit values of water quality indicators prescribed in this Circular shall be based on QCVN 09:2008/BTNMT and QCVN 01:2009/BYT. In case these QCVNs are amended, supplemented, or replaced, the new limit values shall be applied accordingly.

Article 13. Effective Date

1. This Circular takes effect from April 7, 2014.

2. During the implementation process, if there are any difficulties, please promptly report them to the Ministry of Natural Resources and Environment for study and amendment./.